Altered transport properties of pentamidine-resistant Leishmania donovani and L. amazonensis promastigotes

Basselin, Mireille; Lawrence, Françoise; Robert-Géro, Malka

doi:10.1007/s004360050274

Cited by 26 publications

(20 citation statements)

References 31 publications

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“…Cloned wild-type promastigotes were selected for pentamidine resistance by stepwise exposure to the drug until ®nal concentrations of 40 and 20 lM for L. donovani and L. amazonensis, respectively, were reached (Basselin et al 1997). These values were 18 and 75 times higher than the IC 50 (50% inhibitory concentration) of the respective wild types.…”

Section: Selection Of Pentamidine-resistant Promastigotesmentioning

confidence: 99%

“…The resistance was shown to be linked to decreased accumulation of pentamidine accompanied by an alteration in polyamine carriers (Basselin et al 1997) and an important modi®-cation of minicircle nucleotide sequences with a loss of pentamidine-binding sites (Basselin et al submitted for publication). Parallel to decreased drug uptake, other signi®cant modi®cations of the membrane properties are evidenced by decreased transport of structurally unrelated molecules such as pyrimidine nucleosides and several amino acids in the two resistant clones (Basselin et al 1997).…”

Section: Introductionmentioning

confidence: 97%

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Alterations in membrane fluidity, lipid metabolism, mitochondrial activity, and lipophosphoglycan expression in pentamidine-resistant Leishmania

Basselin

Robert-Géro

1997

Parasitology Research

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Cytoplasmic and mitochondrial membranes were studied in wild-type promastigotes of Leishmania donovani and L. amazonensis treated with pentamidine and in the parasites resistant to this drug. Analyses by flow cytometry showed membrane fluidification in resistant cells and a modification of the lipidic metabolism in pentamidine-treated cells and in resistant clones as compared with wild-type ones. Pentamidine decreased the amounts of membrane polar lipids, i.e., phospholipids, and neutral lipidic droplets in the cytoplasm. Perturbation of lipid constituents did not induce modifications of membrane acid phosphatase and protease activities. Lipophosphoglycan, the major cell-surface glycoconjugate, was no longer detected by Western blotting in resistant cells. The use of rhodamine 123 showed a decrease in transmembrane mitochondrial potential in wild-type cells treated with pentamidine and in resistant parasites. In conclusion, cytoplasmic and mitochondrial membranes and lipidic metabolism are altered in pentamidine-resistant parasites.

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Section: Selection Of Pentamidine-resistant Promastigotesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Alterations in membrane fluidity, lipid metabolism, mitochondrial activity, and lipophosphoglycan expression in pentamidine-resistant Leishmania

Basselin

Robert-Géro

1997

Parasitology Research

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“…Other kinetoplastid parasites such as Trypanosoma brucei and Trypanosoma cruzi are reported to have a functional mitochondrial respiratory chain that is essential for survival and growth, although the effects of respiratory chain inhibition are not clear (28). Certain anti-leishmanial drugs such as the aromatic diamidine pentamidine accumulate in the mitochondria (29), and exclusion of the drug from the organelle is linked to drug resistance in the parasite (30). However, the mechanism by which this drug exerts its cytotoxic action and the relationship if any to the respiratory chain are not known.…”

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confidence: 99%

Apoptotic Death in Leishmania donovani Promastigotes in Response to Respiratory Chain Inhibition

Mehta

Shaha

2004

Journal of Biological Chemistry

174

107

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The biochemical changes consequent to respiratory chain inhibition and their relationship to cell death in Leishmania spp. remain elusive. Inhibitors of respiratory chain complexes I, II, and III were able to induce apoptotic death of the bloodstream form of Leishmania donovani. Complex I inhibition resulted in mitochondrial hyperpolarization that was preceded by increased superoxide production. Limitation of electron transport by thenoyltrifluoroacetone and antimycin A, inhibitors of complexes II and III, respectively, resulted in dissipation of mitochondrial membrane potential that was sensitive to cyclosporin A, a blocker of mitochondrial permeability transition pore. Further studies conducted with thenoyltrifluoroacetone showed maximal generation of hydrogen peroxide with a moderate elevation of superoxide levels. 2؉ channel blockers reduced apoptotic death. This study provides a new possibility that concurrent inhibition of respiratory chain complex II with pentamidine administration increases cytotoxicity of the drug. This increased cytotoxicity was connected to a 4-fold elevation in intracellular Ca 2؉ that was pooled only from intracellular sources. Therefore, inhibition of complexes I, II, and III leads to apoptosis and complex II inhibition in parallel with pentamidine administration-enhanced drug efficacy.

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“…L. mexicana (MNYC/BZ/62/ M379) amastigotes were grown at pH 5.5 in Schneider's Drosophila medium (Gibco) supplemented with 20% (vol/vol) heat-inactivated fetal calf serum and gentamicin sulfate at 25 g/ml and 32°C (13). L. mexicana promastigotes resistant to pentamidine were obtained in vitro from sensitive L. mexicana cells by stepwise exposure to the drug with final concentrations of 2.5 M, 5 M, 10 M, and 30 M until they had no effect on parasite growth, as previously described for other Leishmania species (9). L. mexicana amastigotes resistant to pentamidine were obtained axenically by transformation of promastigotes resistant to 30 M pentamidine at 32°C without drug pressure (13).…”

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confidence: 99%

“…Once transformed, parasites were cultivated with 30 M pentamidine. The stability of pentamidine resistance in vitro was determined as described previously (9).…”

mentioning

confidence: 99%

Resistance to Pentamidine in Leishmania mexicana Involves Exclusion of the Drug from the Mitochondrion

Basselin

Denise

Coombs

et al. 2002

Antimicrob Agents Chemother

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134

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The uptake of [3 H]pentamidine into wild-type and drug-resistant strains of Leishmania mexicana was compared. Uptake was carrier mediated. Pentamidine-resistant parasites showed cross-resistance to other toxic diamidine derivatives. A substantial decrease in accumulation of the drug accompanied the resistance phenotype, although the apparent affinity for pentamidine by its carrier was not altered when initial uptake velocity was measured. The apparent V max , however, was reduced. An efflux of pentamidine could be measured in both wild-type and resistant cells. Only a relatively small proportion of the total accumulated pentamidine was available for efflux in wild-type cells, while in resistant cells the majority of loaded pentamidine was available for release. Pharmacological reagents which diminish the mitochondrial membrane potential reduced pentamidine uptake in wild-type parasites, and the mitochondrial membrane potential was shown to be reduced in resistant cells. A fluorescent analogue of pentamidine, 4,6-diamidino-2-phenylindole, accumulated in the kinetoplast of wild-type but not resistant parasites. These data together indicate that diamidine drugs accumulate in the Leishmania mitochondrion and that the development of the resistance phenotype is accompanied by lack of mitochondrial accumulation of the drug and its exclusion from the parasites.

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Altered transport properties of pentamidine-resistant Leishmania donovani and L. amazonensis promastigotes

Cited by 26 publications

References 31 publications

Alterations in membrane fluidity, lipid metabolism, mitochondrial activity, and lipophosphoglycan expression in pentamidine-resistant Leishmania

Alterations in membrane fluidity, lipid metabolism, mitochondrial activity, and lipophosphoglycan expression in pentamidine-resistant Leishmania

Apoptotic Death in Leishmania donovani Promastigotes in Response to Respiratory Chain Inhibition

Resistance to Pentamidine in Leishmania mexicana Involves Exclusion of the Drug from the Mitochondrion

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